Combination treatment of acute myeloid leukemia and myelodysplastic syndrome

ABSTRACT

The present invention relates to the use of Volasertib or a salt thereof or the hydrate thereof in combination with Quizartinib or a salt thereof or the hydrate thereof for treating patients suffering from acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS).

RELATED APPLICATIONS

This application claims the benefit of European Application No. EP 14187331.5, filed Oct. 1, 2014, the entire content of which is incorporated herein by reference in its entirety as though fully set forth herein.

FIELD

The present invention relates to the use of Volasertib or a pharmaceutically acceptable salt thereof or the hydrate thereof in combination with Quizartinib or a pharmaceutically acceptable salt thereof or the hydrate thereof for treating patients suffering from acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

BACKGROUND OF THE INVENTION

Acute myeloid leukemia (AML), also known as acute myelogenous leukemia, is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow and interfere with the production of normal blood cells. As an acute leukemia, AML progresses rapidly and is typically fatal within weeks or months if left untreated. AML is the most prevalent form of adult acute leukemia, particularly among older adults and is slightly more common in men than women. There is an estimated prevalence of 30,000 cases of AML in the US and 47,000 in the EU.

The incidence of AML increases with age with a median age at diagnosis of 67 years. The global incidence CAGR for AML out to 2013 is 1.4%. An aging population, along with an increased incidence of treatment-related AML in cancer survivors, currently accounting for 10-20% of all AML cases, is expected to drive the incidence of AML. In addition, there is some geographic variation in the incidence of AML. In adults, the highest rates are seen in North America, Europe, and Oceania, while adult AML is less frequently diagnosed in Asia and Latin America.

AML accounts for approximately 1.2% of all cancer deaths. The 5 year survival rates for AML are low, driven by therapy failure and patients relapsing. Among patients <65 the 5 year survival rate is 34.4%, among patients >65 it is only 5%.

The WHO classification of myeloid neoplasms and acute leukemia is the current standard for classification of AML and incorporates genetic abnormalities into diagnostic algorithms. This classification is done by examining the appearance of the malignant cells under light microscopy and by using cytogenetics and molecular genetics to characterize any underlying chromosomal abnormalities or genetic changes. The subtypes impact on prognoses, responses to therapy and treatment decisions.

Myelodysplastic syndromes (MDS) are clonal hematopoietic stem-cell disorders characterized by ineffective hematopoiesis, peripheral-blood cytopenias, and increased tendency to progress to acute myeloid leukemia (AML). The age-adjusted incidence of MDS is 3.3 cases per 100,000 people, and this rate appears to be increasing. MDS is primarily a disease of older adults, the median age of patients with MDS is approximately 70 years. This patient population is frequently affected by other comorbid conditions, which often influences treatment decisions. Treatment of MDS is based on prognostic factors that predict survival and progression to AML. Currently, the treatment of patients with MDS is guided by the International Prognostic Scoring System (IPSS). This system stratifies patients into four groups: low, intermediate-1, intermediate-2, and high-risk, based on number of cytopenias, percentage of bone marrow blasts, and karyotype. Low risk and intermediate-1 risk are usually grouped together as lower-risk disease, whereas intermediate-2 risk and high risk are grouped together as higher-risk disease. The survival of patients with higher-risk MDS is significantly different than that of patients with lower-risk disease. Without intervention, median survival of higher-risk patients is close to 12 months. Survival of patients with lower-risk disease is more diverse and ranges from a few months (poor-prognosis, lower-risk disease) to more than a decade. Therefore, the objectives of therapy are different in lower-versus higher-risk disease. While in lower-risk MDS, the goal is to relieve symptoms, manage cytopenias, and minimize the need for transfusions [eg: erythropoiesis-stimulating agents (ESA) and growth factors (GF)], in higher-risk MDS, disease-modifying therapies directed to slowing progression to AML and improving survival are used. These disease modifying therapies include hypomethylating agents (HMA, as e.g. azacitidine), intensive chemotherapy, and allogeneic stem cell transplantation (SCT), with SCT currently being the only known curative modality. Despite these treatment alternatives, the prognosis of patients with higher-risk MDS remains very poor owing to the disappointing activity of standard chemotherapy-based therapies, particularly those with therapy-related MDS, the eventual loss of response to HMA, and the restriction of allogeneic SCT to younger patients with an appropriate donor.

Treatment of higher-risk patients is dependent on whether they are considered to be candidates for intensive therapy (e.g., allogeneic SCT or intensive chemotherapy). Clinical features relevant for this determination include the patient's age, performance status, comorbidities, patient's preference and availability of suitable donor and caregiver. The access to allogeneic SCT is restricted to approximately 8% of patients with MDS, owing to advanced age, concomitant comorbidities and/or donor availability. For higher-risk patients who are not candidates for high-intensity therapy, the use of HMA is considered the standard of care.

The efficacy of chemotherapeutic agents can be improved by using combination therapies with other compounds and/or improving the dosage schedule. Even if the concept of combining several therapeutic agents or improved dosage schedules already has been suggested, there is still a need for new and efficient therapeutic concepts for the treatment of cancer diseases, which show advantages over standard therapies.

Volasertib is a highly potent and selective inhibitor of the serine-threonine Polo like kinase (Plk), a key regulator of cell-cycle progression. Volasertib is a second-generation dihydropteridinone derivative with distinct pharmacokinetic (PK) properties. The problem underlying this invention was to develop a combination treatment and improved dosage schedules for combination therapy of Volasertib and Quizartinib in AML or MDS with maximal activity and limited toxicity.

Volasertib (I) is known as the compound N-[trans-4-[4-(cyclopropylmethyl)-1-piperazinyl]cyclohexyl]-4-[[(7R)-7-ethyl-5,6,7,8-tetrahydro-5-methyl-8-(1-methylethyl)-6-oxo-2-pteridinyl]amino]-3-methoxy-benzamide,

This compound is disclosed in WO 04/076454. Furthermore, trihydrochloride salt forms and hydrates thereof are known from WO 07/090844. They possess properties which make those forms especially suitable for pharmaceutical use. The above mentioned patent applications further disclose the use of this compound or its monoethanesulfonate salt for the preparation of pharmaceutical compositions intended especially for the treatment of diseases characterized by excessive or abnormal cell proliferation.

Document WO 2006/018182 discloses other combinations for the treatment of diseases involving cell proliferation.

Quizartinib is receptor tyrosine kinase inhibitor with the following chemical structure

useful for the treatment of AML. This compound inhibits the protooncogene CD135.

SUMMARY OF THE INVENTION

In animal experiments it has been found that the treatment of Hematologic neoplasms with Volasertib and Quizartinib shows a synergistic efficacy profile (e.g. reduced tumor growth compared to either single agent treatment) and good tolerability of the combination treatment regimen.

Accordingly, a first object of the present invention refers to a pharmaceutical combination comprising Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, and Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for simultaneous, separate or sequential use of the active ingredients.

Another object of the present invention relates to a kit comprising one pharmaceutical composition comprising Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, and another pharmaceutical composition comprising Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS, characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, wherein both active ingredients can be administered simultaneously, separately or sequentially.

Another object of the present invention relates to Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS, characterized in that Quizartinib is administered in combination with Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, wherein both active ingredients can be administered simultaneously, separately or sequentially.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to a dosage schedule (I) comprising or consisting of

-   -   a) administration of an effective amount of Volasertib or a         pharmaceutically acceptable salt thereof or a hydrate thereof on         minimally one day, preferably on two days, during a 4 week         treatment cycle and     -   b) administration of an effective amount of Quizartinib on at         least one day during the said 4 week treatment cycle to a         patient suffering from AML or MDS.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (II)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to dosage schedule (I), wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on day 1 and on one of the days 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or 21 during a 4 week treatment cycle. Preferably, equal doses of Volasertib are administered on both days of administration.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (III)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I) or (II)) wherein in one embodiment 250 to 500 mg, in another embodiment 250, 300, 350, 400, 450 or 500 mg, yet in another embodiment 300 or 350 mg of Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof are administered per day of administration.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (IV)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I), (II) or (III)) wherein Quizartinib is administered on all days during the 4 week treatment cycle.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (V)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I), (II) or (III)) wherein Quizartinib is administered on all days during the 4 week treatment cycle except those days where Volasertib is administered.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (VI)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I), (II) or (III)) wherein Volasertib is administered on day 1 and 15, and Quizartinib is administered on days 2-14 and 16-28 during the 4 week treatment cycle.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (VII)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I), (II) or (III)) wherein Volasertib is administered on day 1 and 15, and Quizartinib is administered on days 3-13 and 17-27 during the 4 week treatment cycle.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (VIII)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I), (II) or (III)) wherein Volasertib is administered on day 1 and 15, and Quizartinib is administered on days 3-13 and 17-27 during the 4 week treatment cycle.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (IX)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I), (II) or (III)) wherein Volasertib is administered on day 1 and 15, and Quizartinib is administered on days 16-28 during the 4 week treatment cycle.

Another object of the present invention relates to Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for use of treating AML or MDS (dosage schedule (X)), characterized in that Volasertib is administered in combination with Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, according to one of the above dosage schedules (dosage schedule (I), (II), (Ill), (IV), (V), (VI), (VII), (VIII) or (IX)) wherein in one embodiment 40-200 mg in another embodiment 50 to 150 mg, in another embodiment 60 mg, 90 mg or 135 mg of Quizartinib are administered per day of administration.

Another object of the invention refers to a method of treating AML or MDS characterized in that Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, and Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, are administered according to one of the dosage schedules (I) to (X).

Another object of the invention refers to the use of Volasertib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for the manufacture of a medicament for treating AML or MDS in patients suffering from AML or MDS wherein the medicament is prepared for administration according to one of the dosage schedules (I) to (X).

Another object of the invention refers to the use of Quizartinib, optionally in the form of a pharmaceutically acceptable salt thereof or a hydrate thereof, for the manufacture of a medicament for treating AML or MDS in patients suffering from AML or MDS wherein the medicament is prepared for administration according to one of the dosage schedules (I) to (X).

Another object of the invention is a pharmaceutical composition comprising an effective amount of Volasertib and an effective amount of Quizartinib, optionally together with an instruction for administration of both active ingredients to a patient suffering from AML or MDS, wherein according to said instruction Volasertib is to be administered according to the above mentioned dosage schedules (I) to (X).

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the tumor growth kinetics in a nude mouse xenograft model derived from human AML cell line MV4;11. Tumor-bearing mice were treated for 2 weeks either with vehicle or with 20 mg/kg Volasertib (BI 6727) once a week i.v., 5 mg/kg or 10 mg/kg Quizartinib daily administered p.o. or a combination of Volasertib and Quizartinib. Median tumor volumes are plotted over time. Day 1 was the first day, day 87 the last day of the experiment. Efficacy results from this xenograft models are considered valid for AML as well as MDS.

DETAILED DESCRIPTION OF THE INVENTION

In case Volasertib is administered on minimally two days during a 4 week treatment cycle, then Volasertib is administered on two non-consecutive days during a 4 week treatment cycle.

The administration of an effective amount of Quizartinib on at least one day of the said 4 week treatment cycle means that during the 4 week treatment cycle in which Volasertib is administered minimally one time, also Quizartinib is administered on at least one day.

Preferably, Quizartinib is administered on every day during the 4 week treatment cycle.

The administration of Volasertib on day 1 and 15 during a 4 week treatment cycle means that one dosage of Volasertib or a pharmaceutically acceptable salt or a hydrate thereof is administered on day one and the second dosage is administered on day 15 to the patient suffering from AML or MDS in the four week treatment cycle.

Accordingly, a complete four week treatment cycle according to one of the above mentioned dosage schedules may comprise the following administrations:

-   -   Day 1: one dosage of Volasertib (e.g. 300 or 350 mg) and one         dosage of Quizartinib (e.g. 40-200 mg);     -   Day 2 to day 14 (including): one dosage of Quizartinib (e.g.         40-200 mg) per day;     -   Day 15: one dosage of Volasertib (e.g. 300 or 350 mg) and one         dosage of Quizartinib (e.g. 40-200 mg);     -   Day 16 to day 28 (including): one dosage of Quizartinib (e.g.         40-200 mg) per day.

This treatment cycle can be repeated as long as patients are eligible for repeated cycles, i.e. until relapse, progression of disease and as long as neither patient nor investigator requests treatment discontinuation.

The instruction for coadministration may be in any form suitable for pharmaceuticals, e.g. in form of a leaflet added to the dosage form within secondary packaging or an imprint on the primary or secondary packaging.

Dosages/Volasertib:

For intraveneous treatment Volasertib may be administered to the human patient in a daily dose of 250 to 500 mg/application, preferably 250, 300, 350, 400, 450 or 500 mg/application, more preferably 300 or 350 mg/application. For instance, Volasertib can be administered as a slow intravenous infusion over several hours, e.g. over about 1, 2, 4, 6, 10, 12 or 24 hours, preferably about 1 or 2 hours.

Dosages/Quizartinib:

Quizartinib may be administered in a total daily dose of 40 to 200 mg, e.g. in a total daily dose of 40, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190 or 200 mg one time daily. The total daily dose may also be divided into two or three subdoses to be taken within one day. Preferably, the daily dose is administered in a single dose of 135 mg for male patients and 90 mg for female patients.

However, it may optionally be necessary to deviate from the dosage amounts specified for Volasertib and Quizartinib, depending on the body weight on the method of administration, the individual response to the medication, the nature of the formulation used and the time or interval over which it is administered. Thus, in some cases, it may be sufficient to use less than the minimum quantity specified above, while in other cases the upper limit specified will have to be exceeded. When large amounts are administered it may be advisable to spread them over the day in a number of single doses.

Dosage Forms and Formulation Aspects

Regarding any aspects of the invention for Volasertib pharmaceutically acceptable salts or hydrates thereof may be used, preferably trihydrochloride salt forms and hydrates thereof as disclosed in WO 07/090844. Dosages or amounts of the active ingredient provided in the context of this invention refer in any case to the free base equivalent, that is Volasertib in the free base form.

The term “therapeutically effective amount” shall mean that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue system, animal or human that is being sought by a researcher or clinician, resulting in a beneficial effect for at least a statistically significant fraction of patients, such as an improvement of symptoms, improvement of peripheral blood cell counts, a cure, a reduction in disease load, reduction in tumor mass or leukaemia cell numbers, extension of life, or improvement in quality of life.

Day 1 of a 4 week treatment cycle is defined as that day on which the first dose of Volasertib administered.

Within the present invention the term “AML” is to be understood to encompass all forms of acute myeloid leukemia and related neoplasms according to the 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia. These are:

-   -   Acute myeloid leukemia with recurrent genetic abnormalities         -   AML with t(8;21)(q22;q22); RUNX1-RUNX1T1         -   AML with inv(16)(p13.1q22) or t(16;16)(p13.1;q22);             CBFB-MYH11         -   AML with t(9;11)(p22;q23); MLLT3-MLL         -   AML with t(6;9)(p23;q34); DEK-NUP214         -   AML with inv(3)(q21 q26.2) or t(3;3)(q21;q26.2); RPN1-EVI1         -   AML (megakaryoblastic) with t(1;22)(p13;q13); RBM15-MKL1         -   Provisional entity: AML with mutated NPM1         -   Provisional entity: AML with mutated CEBPA     -   Acute myeloid leukemia with myelodysplasia-related changes     -   Therapy-related myeloid neoplasms     -   Acute myeloid leukemia, not otherwise specified         -   AML with minimal differentiation         -   AML without maturation         -   AML with maturation         -   Acute myelomonocytic leukemia         -   Acute monoblastic/monocytic leukemia         -   Acute erythroid leukemia             -   Pure erythroid leukemia             -   Erythroleukemia, erythroid/myeloid         -   Acute megakaryoblastic leukemia         -   Acute basophilic leukemia         -   Acute panmyelosis with myelofibrosis     -   Myeloid sarcoma     -   Myeloid proliferations related to Down syndrome         -   Transient abnormal myelopoiesis         -   Myeloid leukemia associated with Down syndrome     -   Blastic plasmacytoid dendritic cell neoplasm

Within the present invention the term “MDS” is to be understood to encompass all forms of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) and myelodysplastic syndromes according to the 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia. These are:

-   -   Myelodysplastic/myeloproliferative neoplasms (MDS/MPN)         -   Chronic myelomonocytic leukemia         -   Atypical chronic myeloid leukemia, BCR-ABL1-negative         -   Juvenile myelomonocytic leukemia         -   Myelodysplastic/myeloproliferative neoplasm, unclassifiable         -   Provisional entity: refractory anemia with ring sideroblasts             and thrombocytosis     -   Myelodysplastic syndrome (MDS)         -   Refractory cytopenia with unilineage dysplasia         -   Refractory anemia         -   Refractory neutropenia         -   Refractory thrombocytopenia         -   Refractory anemia with ring sideroblasts         -   Refractory cytopenia with multilineage dysplasia         -   Refractory anemia with excess blasts         -   Myelodysplastic syndrome with isolated del(5q)         -   Myelodysplastic syndrome, unclassifiable         -   Childhood myelodysplastic syndrome         -   Provisional entity: refractory cytopenia of childhood

In accordance with the present invention Volasertib may be administered by parenteral (e.g. intramuscular, intraperitoneal, intravenous, transdermal or subcutaneous injection), and may be formulated, alone or together, in suitable dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles appropriate for each route of administration. Dosage forms and formulations of both active ingredients suitable within the present invention are known in the art. For instance, such dosage forms and formulations include those disclosed for Volasertib in WO 2006/018221.

In accordance with the present invention Quizartinib may be administered by oral routes of administration and may be formulated, alone or together, in suitable dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles appropriate for each route of administration.

The following Examples serve to illustrate the invention without restricting it:

Cells

MV4;11 (CRL-9591) cells were obtained from ATCC. According to the Catalogue of Somatic Mutations in Cancer of the Wellcome Trust Sanger Institute, UK, this cell line carries a mutation in the FLT3 gene. Cells were cultured in T175 tissue culture flasks at 37° C. and 5% CO2. The medium used was IMDM supplemented with 10% fetal calf serum, 1% NEAA, 1% sodium pyruvate and 1% glutamine.

Mice

Mice were 8 week-old athymic female BomTac: NMRI-Foxn1^(nu) purchased from Taconic, Denmark. After arrival in the animal facility, mice were allowed to adjust to ambient conditions for at least 3 days before they were used for experiments. They were housed in Macrolon® type II cages in groups of 5 under standardized conditions at 21.5±1.5° C. temperature and 55±10% humidity. Standardized diet (PROVIMI KLIBA) and autoclaved tap water were provided ad libitum.

Establishment of Tumors, Randomization

To establish subcutaneous tumors, MV4;11 cells were harvested and resuspended in PBS+5% FCS at 5×10⁷ cells/ml. 50 μl of the cell suspension containing 2.5×10⁶ cells was then injected subcutaneously into the right flank of the mice (1 site per mouse). Growth factor reduced BD Matrigel™ Matrix (BD Biosciences) was added to the cell suspension at a ratio of 1:1 before the injection. When tumors were well established and had reached a tumor volume of ˜180 mm³, mice were randomly distributed between the treatment and the vehicle control groups 14 days after injecting the cells.

Administration of Test Compounds

Volasertib was dissolved in hydrochloric acid (0.1 N), diluted with 0.9% NaCl and injected intravenously into the tail vein. An administration volume of 10 ml per kg body weight was used. The solution was freshly made up each injection day. Quizartinib was dissolved in 22% HP-β-CD and administered p.o. An administration volume of 10 ml per kg body weight was used.

The application solution was prepared for one week of treatment and kept at 4° C.

Monitoring Tumor Growth and Side Effects

The tumor diameter was measured three times a week with a caliper. The volume of each tumor [in mm³] was calculated according to the formula “tumor volume=length*diameter²*π/6”. To monitor side effects of treatment, mice were inspected daily for abnormalities and body weight was determined three times a week. Control animals and animals of the single agent Volasertib treatment arm were sacrificed when the control tumors reached a size of approximately 1400 mm³ on average. Animals of the Quizartinib single agent and combination treatment arms were sacrificed when the tumors reached a size of approximately 1400 mm³ or at the end of the study.

Example 1 Nude Mouse Xenograft Model Derived from Human AML Cell Line MV4;11

Results of an experiment comparing treatment of xenografts in mice with Volasertib alone (20 mg/kg), administered once weekly, Quizartinib alone (5 or 10 mg/kg), administered daily, and the combination of Volasertib (20 mg/kg once a week)/Quizartinib (5 or 10 mg/kg administered daily) are shown in FIG. 1. Animals were treated for 14 days followed by an observation period without treatment up to day 87. FIG. 1 shows the outgrowth of the tumor from the treatment groups with single agent quizartinib, but maintained tumor control until the end of the study in the combination arms. Further, a beneficial side effect profile was demonstrated as body weight gain in the combination group was comparable to single-agent Quizartinib. 

The invention claimed is:
 1. A method of treating a patient suffering from myeloid leukemia (AML) and/or myelodysplastic syndrome (MDS), comprising: administering to the patient Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof, wherein the Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof are administered simultaneously, separately or sequentially.
 2. The method of claim 1, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof, are administered according to a dosage schedule (I), comprising: a) administration of a therapeutically effective amount of Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof on minimally one day during a 4 week treatment cycle and b) administration of a therapeutically effective amount of Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof on at least one day of the said 4 week treatment cycle, to the patient.
 3. The method of claim 1, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof are administered according to a dosage schedule (I), comprising: a) administration of a therapeutically effective amount of Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof on minimally two days during a 4 week treatment cycle and b) administration of a therapeutically effective amount of Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof on at least one day of the said 4 week treatment cycle, to the patient.
 4. The method of claim 1, wherein 250 to 500 mg of Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered per day of administration.
 5. The method of claim 1, wherein 40 to 200 mg of Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered per day of administration.
 6. The method of claim 1, wherein Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on all days during the 4 week treatment cycle.
 7. The method of claim 2, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on day 1 and 15, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on days 2-14 and 16-28 during the 4 week treatment cycle.
 8. The method of claim 2, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on day 1 and 15, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on days 3-13 and 17-27 during the 4 week treatment cycle.
 9. The method of claim 2, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on day 1 and 15, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on days 16-28 during the 4 week treatment cycle.
 10. The method of claim 3, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on day 1 and 15, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on days 2-14 and 16-28 during the 4 week treatment cycle.
 11. The method of claim 3, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on day 1 and 15, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on days 3-13 and 17-27 during the 4 week treatment cycle.
 12. The method of claim 3, wherein Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on day 1 and 15, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof is administered on days 16-28 during the 4 week treatment cycle.
 13. A pharmaceutical composition comprising an effective amount of Volasertib or a pharmaceutically acceptable salt thereof or a hydrate thereof, and an effective amount of Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof.
 14. The pharmaceutical composition according to claim 13 for treating AML and/or MDS.
 15. A pharmaceutical combination comprising Volasertibor a pharmaceutically acceptable salt thereof or a hydrate thereof, and Quizartinib or a pharmaceutically acceptable salt thereof or a hydrate thereof, for simultaneous, separate or sequential administration to and treatment of a patient suffering from AML and/or MDS. 